Recently, a flexible circuit board has gradually replaced a coaxial cable, which has been used for the purpose of transmitting a high frequency signal as a component of wireless terminals such as a smartphone and a tablet personal computer (PC).
In addition, surface mounter technology (SMT) has been used as a method of bonding the flexible circuit board to a printed circuit board.
As shown in FIG. 1, according to the SMT, a flexible circuit board 10 is mounted on a printed circuit board 20, and the flexible circuit board 10 and the printed circuit board 20 are coupled by thermally melting solder 22 between a flexible circuit board ground pad 11 formed below the flexible circuit board 10 and a printed circuit board ground pad 21 formed on the printed circuit board 20.
However, when the flexible circuit board 10 is not properly mounted on the printed circuit board 20, the SMT is not properly performed.